Method and system for upload optimization

ABSTRACT

A technique for manipulating one mobile device (MD) from a plurality of MDs to maintain the transmitting rate of packets of an upload session to one Internet Protocol (IP) server from a plurality of IP servers is disclosed. The technique may utilize an upload-rate-controlling server that is communicatively coupled between the plurality of MDs and the plurality of IP servers and is configured to respond to missing one or more packets by using SACK and DSACK messages. Other embodiments may estimate the delay of the uploaded packets and adapt the value of a new-receiving window such that the delay of the uploaded packets is smaller than the value of the time threshold used by intermediate nodes for dropping packets.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a utility patent application being filed in the United States asa non-provisional application for patent under Title 35 U.S.C. § 100 etseq. and 37 C.F.R. § 1.53(b) and, claiming the benefit of the priorfiling date under Title 35, U.S.C. § 119(e) of the United Statesprovisional application for patent that was filed on May 29, 2016 andassigned Ser. No. 62/342,964, which application is incorporated hereinby reference in its entirety.

FIELD OF THE DISCLOSURE

The present disclosure generally relates to the field of datacommunication over a packet switch network such as Internet Protocol(IP) packets. More particularly the disclosure relates to transmissionrate control of IP packets during uploading data from a mobile device.

DESCRIPTION OF BACKGROUND ART

In the past the Internet was used as non-symmetrical network, in whichmost of the data traffic was directed from the Internet servers towardthe users' devices. Accordingly, common flow control and load controlmethods are designed to control the traffic from an Internet servertoward a user device. For example, Internet servers are configured touse a congestion-avoidance-control mechanism. In some cellular networks,intermediate nodes may use congestion-avoidance-control mechanism suchas Active Queue Management (AQM) in order to control their contributionto the current load over the connection. Thecongestion-avoidance-control mechanism controls the rate of dataentering the network from that server and keeping the data flow below arate that would trigger unmanaged congestion event. In addition,congestion-avoidance-control mechanism and/or AQM technique also used tofairly allocate resources among downstream flows.

On the other end, user devices are designed to control the downloadedrate of their own flow according to the current capabilities of the userdevices. For example, controlling the download rate of flows over aTCP/IP connection to a client, the client is designed to change the sizeof the “receive window” parameter that the client sends toward anInternet server. Thus, limiting the number of transmitted bytes that canbe sent from a web server, between two consecutive acknowledgements thatwere sent from the client. A TCP/IP connection stands for TransmissionControl Protocol over Internet Protocol network. Along the disclosureand the claims the terms “receive window” or “advertising window” can beused interchangeably.

In addition, intermediate nodes or servers, between a user device and aweb server, which delivers the requested data, are configured to use acongestion-avoidance-control mechanism, thus an intermediate node hasits own buffers and is configured to drop packets, when the buffersreach a certain limitation. Some of those intermediate servers controlthe buffers based on a threshold that is defined in number of bytes andsome of the servers are configured to control the buffer based onlatency values. Along the disclosure and the claims the terms “packet”or “byte” can be used interchangeably.

Today the Internet becomes more and more symmetrical. There are more andmore applications in which a user can upload a large volume of datatoward an Internet server. Some of those applications compriseapplications such as but not limited to “Facebook” or “Instagram”(Facebook and Instagram are trademarks of Facebook Inc. USA) that allowuploading of images, video images, etc. Today, even emails can carry alarge volume of data, images, files etc. Further, there are applicationsthat allow real-time communication sessions, such as but not limited tochat, video or audio conferencing, etc. that have symmetrical upload anddownload volume of data.

In an uploading session a user device acts as a server and sends IPpackets toward the Internet. While the destination server acts as aclient that is configured to receive those packets. However, a commonuser device is configured to use common TCP/IPcongestion-avoidance-control mechanism, which is not optimized foruploading session in dynamic networks. A cellular access network can beused as an example of a dynamic network, in which bandwidth (BW) and thelatency are changed dynamically. Consequently, buffers in between theuser device and the destination server can reach their bufferlimitations and start dropping packets.

In TCP/IP connection, dropping packets will cause lost packet indicationfrom the destination, which will follow by retransmission and reducingdramatically the bitrate of the transmission. In common TCP/IPconnection the congestion window can be reduced up to half of theprevious value. Thus, increasing the upload time and reducing theexperience of the user. The congestion window is used by thetransmitting side to limit the number of bytes sent and not acknowledgedyet.

Further, more and more users use their smart phones in order tocommunicate over the Internet and upload data such as video or images.Images and video that are captured by the smartphone camera, forexample. Common cellular intermediate nodes that are located in betweenthe mobile device and the Internet, at the cellular operator premises,are configured to have tight buffer limitations. Some of those bufferlimitations are volume related (their threshold is given in number ofbytes) other buffer limitations are time related. An intermediate node,which uses time domain limitation, can be configured to drop packetsthat are stored in buffers more than a certain limit. For example bufferlimitation that is used over a connection between a mobile device and anLTE operator premises may be given in time domain. Usually intermediatenodes, at LTE networks, are configured to drop stored packets which arestored more than 200 milliseconds, for example. LTE stands for 3GPP LongTerm Evolution, which is also referred as 4G. An example of anintermediate node can be EnodeB (Evolved Node B) of an LTE cellularoperator.

BRIEF SUMMARY

The needs and the deficiencies that are described above are not intendedto limit the scope of the inventive concepts of the present disclosurein any manner. The needs are presented for illustration only. Thedisclosure is directed to a novel technique for controlling thetransmission rate, from a user's device in an upload session, by anintermediate node. Wherein the intermediate node is located between theuser's device and an IP server. Along the description and the claims theterms upload and upstream can be used interchangeably. Along thedisclosure and the claims the terms “user's device” or “mobile device”can be used interchangeably.

Dropping packets of TCP/IP of uploading flow of packets at intermediatenodes between a user's device, such as but not limited to a mobiledevice, and the Internet access network at a cellular operator premisescauses inefficient usage of radio resources over the expensive cellularconnection and increases the upload time. Consequently, reducing thepackets loss in flows of upload sessions is a common interest of theoperator as well as the user. However, the congestion-avoidance-controlmechanism of a user device is not adapted to the dynamic of a commoncellular access network. An example of an intermediate node can beEnodeB (Evolved Node B) of an LTE cellular operator; or node B in 3G orany similar intermediate node over other mobile networks.

In order to reduce the packet loss in between a user device and theaccess network of a cellular operator, an example embodiment of anupload-rate-controller server (URCS) can be installed in an accessnetwork between the mobile devices and the Internet. An example of anURCS can be configured to control the transmission rate of one or moreflows of packets from a user device during an upload TCP/IPcommunication session in order to reduce the packet loss over the uploadconnection between the user's device and the URCS.

An example of URCS can be configured to estimate the delay over anupload connection between a user device and the URCS. Based on theestimated delay the URGS may control the user's device transmission ratein order to keep the delay over an upload connection, with the mobiledevice, below a certain time limitation, a certain time threshold.Wherein the value of the time threshold is smaller than the value of thetime threshold used by buffers along the upload connection.

An example embodiment of the disclosed technique can be based on anassumption that the time it takes to transmit or receive, by the user'sdevice or the URCS, the amount of bytes, which is limited by the valueof the receive window, is smaller than the latency over the buffersalong the connection. For such a case the receive window of the URCS maybe calculated as a function of the time threshold (TT) for droppingpackets that is used by the intermediate nodes of the cellular operatorand the rate that the packets reach the URCS. A common value for TT canbe between 100 to 200 milliseconds, for example. In some networks thevalue of TT can be up to few seconds.

From time to time an example of URCS can count the amount of bytes thatare obtained (NoBY) during a measuring period (MP). The MP can be aportion of TT, MP=TT divided by ‘n’ (MP=TT:n); the value of ‘n’ can beany number in the range of three to ten, such as five, for example.Other embodiments may use other values or other ranges for ‘n’. Based onthe NoBY, an example embodiment can set the value of its receive windowto the product of the NoBY by the factor ‘n*k’, where k is a tuningfactor. An example value of k can be in the range between 0.5 and 2. Thenext receive window (NRW) can be set to the value of the product of NoBYby n and by k, NRW=NoBY*(n*k).

In some embodiments number of packets may be used instead of NoBY(number of obtained bytes). In some embodiments several consecutivemeasurements can be done and the highest value of NoBY per MP can beused.

Other embodiments of URCS may calculate the value of the receive windowbased on the assumption that the delay of the packets, the latency timealong a connection between a user device and the URCS, is a function ofthe propagation delay over the connection, between the mobile device andthe URCS, and the load over the one or more intermediate nodes such asone or more EnodeB that are located in between the mobile device and theURCS.

Such example embodiment of an URCS, can estimate the delay over theconnection with the user device by estimating the value of RTT (roundtrip time) along the connection. The RTT can be estimated once duringestablishing the TCP/IP connection between the user's device and theURCS by measuring the time interval of a TCP 3-Way handshake. The timeinterval between Syn.; Syn-Ack; and Ack. TCP 3-Way handshake is wellknown to a person having ordinary skill in the art and will not befurther disclosed. Consequently the RTT reflects the delay over thecommunication link between the transmitting device and the receivingdevice. The RTT value can be used as a good estimation for the currentdelay over the connection between the user's device and the URCS. Thecurrent delay is a function of the propagation delay and the delay inthe buffers in one or more intermediate nodes.

In order to measure the RTT during the ongoing upload session, anexample embodiment of a URCS can be configured to measure the timeinterval between sending an ACK with a receive window, which is largerthan the current receive window, waiting to get the number of bytes,according to the parameter used by the larger receive window. Thisnumber is larger than the current receive window by one, for example.Other embodiments may use other factors than one. Indicating that thisbunch is related to the new value of the receive window. This timeinterval can be used as an estimate value of the current RTT from whichthe latency over the connection can be calculated.

Next, the example embodiment of an URCS can estimate how many uploadingdata bytes are needed in order to reach the time limitation of thebuffers in the intermediate nodes between the user's device and theURCS. According to the estimated number of bytes the example of URCS canadapt the value of it's receive window and inform the user's deviceabout the new value of the receive window. A safety factor can be usedwhile defining the receive window in order to avoid byte dropping in thebuffers of the intermediate nodes.

An example embodiment of the disclosed URCS can calculate a requiredreceive window, which can prevent dropping of bytes in intermediatenodes between the user device and the URCS during uploading session. Anexample process for estimating the receive window can comprise:obtaining or defining the time threshold (TT) used in the intermediatenodes; obtaining or defining a value for the propagation delay (PD)along the connection between the user's device and the URCS. The valuesof the PD and/or TT can be found in the literature of the cellularoperator, or of the technical equipment used in the intermediate nodes.In addition a safety factor can be used.

Example embodiments of the present disclosure can define a measuringperiod (MP), 50 milliseconds for example. The values of MP can be in therange of few tens of milliseconds, 10-70 milliseconds for example.During the MP an example embodiment of the disclosed URCS can count theamount of obtained bytes. Next, the example of URCS can repeat countingthe number of obtained bytes in few consecutive MPs, 5-10 periods ofMPs, for example. Then, a MAX value of the obtained bytes per MP can bedefined and a new value NRW can be set to NRW=(TT:MP)*MAX. From time totime an example embodiment of a URCS can be configured to repeat theprocess of setting the value of the NRW for adapting it according to thedynamic of the network.

Some example embodiments of the disclosed URCS may be configured torespond to a packet loss by reporting on the loss in a first and asecond acknowledge packets. The first acknowledge packet (ACK) can be aSelective ACK (SACK) indicating missing of one or more packets. Thesecond acknowledge packet can be a Duplicate-Selective ACK (DSACK).Using a DSACK in response to missing one or more packets is tricky andtargeted to avoid reducing the congestion window, and hence thetransmitting rate by the user's device. By using the DSACK, an exampleembodiment of URCS cheats the user's device and spoofs it to concludethat the missing packets were not missed and just arrived later-on, outof order. Such a conclusion at the user's device, during an uploadsession, will prevent reducing the congestion window, and hence thereducing of the transmitting rate, and neutralizes the rate controlmechanism at the user's device during an upload session.

The foregoing summary is not intended to summarize each potentialembodiment or every aspect of the present invention. Other features andadvantages of the present invention will become apparent upon readingthe following detailed description of the example embodiments with theaccompanying drawings and appended claims.

Furthermore, although specific example embodiments are described indetail to illustrate the inventive concepts to a person skilled in theart, such embodiments can be modified to various modifications andalternative forms. Accordingly, the figures and written description arenot intended to limit the scope of the inventive concepts in any manner.

Other objects, features, and advantages of the present disclosed systemwill become apparent upon reading the following detailed description ofthe embodiments with the accompanying drawings and appended claims.

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

Exemplary embodiments of the present disclosure will be understood andappreciated more fully from the following detailed description, taken inconjunction with the drawings in which:

FIG. 1 illustrates a block diagram with relevant elements of an exampleAccess Network Operator Premises in which an exemplary embodiment of thepresent disclosure can be implemented;

FIG. 2 illustrates a block diagram with relevant elements of an exampleof an upload-rate-controller server (URCS), according to the teaching ofthe present disclosure;

FIG. 3 illustrates a flowchart with relevant actions of a process thatcan be implemented by an example of TCP proxy, according to the teachingof the present disclosure;

FIG. 4 illustrates a flowchart with relevant actions of an examplemanaging process that can be implemented by an example of a managermodule, according to the teaching of the present disclosure; and

FIG. 5 illustrates a flowchart with relevant actions of an example ratecontrolling process that can be implemented by an example of a user'smobile-device-rate controller module (UMDRC), according to the teachingof the present disclosure.

DETAILED DESCRIPTION OF EMBODIMENTS OF THE INVENTION

Turning now to the figures in which like numerals represent likeelements throughout the disclosed several exemplary embodiments of thepresent disclosure. For convenience, only some elements of the samegroup may be labeled with numerals. The purpose of the drawings is todescribe exemplary embodiments and not for production. Thereforefeatures shown in the figures are chosen for convenience and clarity ofpresentation only. Moreover, the language used in this disclosure hasbeen principally selected for readability and instructional purposes,and may not have been selected to delineate or circumscribe theinventive subject matter, resort to the claims being necessary todetermine such inventive subject matter.

Reference in the specification to “one embodiment” or to “an embodiment”means that a particular feature, structure, or characteristic describedin connection with the embodiments is included in at least oneembodiment of the invention, and multiple references to “one embodiment”or “an embodiment” should not be understood as necessarily all referringto the same embodiment.

Although some of the following description is written in terms thatrelate to software or firmware, embodiments may implement the featuresand functionality described herein in software, firmware, or hardware asdesired, including any combination of software, firmware, and hardware.In the following description, the words “unit,” “element,” “module” and“logical module” may be used interchangeably. Anything designated as aunit or module may be a stand-alone unit or a specialized or integratedmodule. A unit or a module may be modular or have modular aspectsallowing it to be easily removed and replaced with another similar unitor module. Each unit or module may be any one of, or any combination of,software, hardware, and/or firmware, ultimately resulting in one or moreprocessors programmed to execute the functionality ascribed to the unitor module. Additionally, multiple modules of the same or different typesmay be implemented by a single processor. Software of a logical modulemay be embodied on a computer readable medium such as a read/write harddisc, CDROM, Flash memory, ROM, or other memory or storage, etc. Inorder to execute a certain task a software program may be loaded to anappropriate processor as needed. In the present disclosure the termstask, method, and process can be used interchangeably.

FIG. 1 depicts a block diagram with relevant elements of a communicationnetwork 100 in which an example embodiment of the present disclosure canbe implemented. Network 100 can comprise an Access Network OperatorPremises (ANOP) 130. The Access-Network Operator can be a cellularoperator, a telecom operator, an Internet provider, a satellitecommunication service provider, a Public Switched Telephone Network(PSTN) operator, etc. Other exemplary embodiments of the presentdisclosure can be installed at an Internet Service Provider (ISP)premises, and so on.

An ANOP 130 can provide different services to a plurality of differentsurfers (or to the mobile device utilized by a surfer) MD 110. A fewnon-limiting examples of typical MD 110 can be: a laptop, a mobilephone, a PDA (personal digital assistance), smart phone, a tabletcomputer, etc. A few non-limiting examples of services provided by anANOP 130 can include: spam filtering, content filtering, bandwidthconsumption distribution, transcoding, upload-rate adaptation, etc.

An exemplary ANOP 130 can be used as an intermediate node between theplurality of MDs 110 and the Internet 140. Among other elements, anexample of ANOP 130 may comprise: an access gateway (AGW) 134; an URCS136 and a border gateway (BGW) 138. An example of AGW 134 can beconfigured to identify the plurality of MD 110 at its ingress, forexample. A few non-limiting examples of an AGW 134 may include: aServing GPRS Support Node (SGSN) in a GSM network, a PDSN in a CDMAnetwork, etc. In LTE network an example of an AGW 134 can be aPacket-Data-Network (PDN) Gateway. An example of AGW 134 is required to:identify the services being requested by a surfer; identify the servicesa subscriber is entitled to receive; route traffic of the subscriberthrough the appropriate services; and output processed data toward thesubscriber or the Internet, for example.

An MD 110 can be connected to the AGW 134 via different communicationlinks 120 and intermediate nodes such as but not limited to EnodeB 132.The communication links 120 can be such as but not limited to: wirelesslinks, cellular links, and so on. The BGW 138, at the output of ANOP 130toward the Internet 140 can be an Internet Protocol router, for example.The BGW 138 can be connected to a plurality of web-servers 150 via an IPnetwork such as the Internet 140, for example. The BGW 138 can also beconnected to private packet data networks (not shown in the figures)such as, but not limited to an Intranet, LAN, WAN, etc. Thecommunication between the BGW 138 and the web-servers 150 and/or theprivate packet data network can be packet oriented, which can be basedon the Internet Protocol (IP), for example.

An example of URCS 136 can be configured to receive data packetcommunication transmitted between the plurality of MDs 110 and theplurality of servers 150 located at network 140 via the AGW 134 and BGW138, respectively. In the upload direction, the AGW 134, can interceptpackets received from the MD 110, identify packets that belong touploading sessions and forward them toward the URCS 136. Packets that donot belong to upload sessions can be transferred toward its destinationvia BGW 138. Packets that belong to “Facebook” or “Instagram”, chat,videoconferencing, etc. applications can be used as non-limitingexamples of sessions that have high volume of uploading data.

An example of URCS 136 can be configured to fulfil the task of a ratecontroller on behalf of a targeted web server at an uploading session.Such an URCS 136 can be configured to maintain the upload transmittingrate of the MD 110. Maintaining the upload transmitting rate along thepath between a MD 110 and a web server 150 improves the bandwidthconsumption over expensive wireless connection and improves the customersatisfaction during upload sessions. More information on the operationof an example of URCS 136 is disclosed below in conjunction with FIGS. 2to 5.

FIG. 2 depicts a block diagram with relevant elements of an exampleembodiment of an Upload-Rate-Controller Server (URCS) 200. An example ofURCS 200 can comprise a TCP proxy 210, a surfing-session table (SST)215, a plurality of User's-Mobile-Device-rate controller (UMDRC) 220a-c, and a manager module (MM) 230. In addition URCS 200 can beassociated with one or more databases not shown in the figures.

An example of a TCP proxy 210 can be a transparent TCP proxy. In onedirection, the TCP proxy 210 can receive a plurality of request packets,from different surfers using MDs 110 (FIG. 1). Each obtained packet, ofa new connection, can be processed by the TCP proxy 210. Based onparsing the header of the packet, the TCP proxy 210 can determine thetype of the obtained packet. If the type of the obtained packet is arequest to establish an upload session, then the request can betransferred toward a queue of the MM 230 for further processing. The MM230 process can comprise allocating an appropriate UMDRC 220 forcontrolling the rate of the upload packets. An entry in the SST 215 canbe allocated for that upload session and the allocated UMDRC 220 can bemarked as the next hop for the following packets of that session.

In addition, an example of TCP proxy 210 can be configured to reduce theamount of retransmissions of missing packets, in an upload session, byspoofing the relevant MD 110 that packets arrived out of order and notwere dropped along the connection. More information on the operation ofan example embodiment of TCP proxy 210 is disclosed below in conjunctionwith FIG. 3.

If the obtained packet is not a request to establish an upload session,then the SST 215 can be updated with a new entry, which is assigned forthe new session. A field in the SST that is associated with the sessiontype can be updated as a non-upload session and the packet can betransferred toward its destination via the TCP proxy 210. Followingpackets of the same session can be transferred directly toward theirdestination.

An example of a UMDRC 220 a-c can comprise a plurality of threads 220one per each upload session. An example embodiment of UMDRC 220 can beconfigured to estimate the delay over the upload connection between theuser device and the URCS and to control the user's device's transmissionrate in order to keep the delay over the connection with the mobiledevice below the relevant time limitation, time threshold, of buffersalong the connection between the user device 110 (FIG. 1) and therelevant server 150 in order to avoid dropping packets by theintermediate nodes 132. An example of UMDRC 220 can be configured tocontrol the upload rate by changing the size of the receive windowaccording to the current condition over the connection. More informationon the operation of an example embodiment of UMDRC 220 is disclosedbelow in conjunction with FIG. 5.

An example embodiment of a Manager Module (MM) 230 can allocate aplurality of computing and storage resources that can be needed by theURCS 200 for its operation. Resources such as but not limited to storageresources used by the SST 215, computing resources that are used by theplurality of UMDRC 220, etc. An exemplary embodiment of the MM 230 canperiodically scan the SST and release resources that are no longerrequired (i.e. resources which were allocated to sessions which are notactive along a configurable period of time). The MM 230 can communicatewith other servers in the ANOP 130 (FIG. 1) for management informationand/or for communicating status and control data. More information onthe operation on the MM 230 is disclosed below in conjunction with FIG.4.

FIG. 3 illustrates a flowchart with relevant actions that can beimplemented by an example embodiment of a TCP proxy 210 (FIG. 2) duringan upload session. The upload session is directed from an MD 110 towarda web server 150 (FIG. 1), for example. The process 300 can commenceupon initiating a relevant URCS 200 (FIG. 2) and be executed by the TCPproxy 210 (FIG. 2), for example. Upon initiation 302 process 300 maycheck its input queue looking for 304 a next packet in the queue. If 304there is no packet the checking process 304 can be executed in a loopuntil a packet is obtained.

Upon obtaining a packet 304, the header of the packet can be parsed anda decision can be made 306 whether the packet is obtained from the AGW134 or from the BGW 138 (FIG. 1) or from an internal module (UMDRC 220or the MM 230) of URCS 200 (FIG. 2). Packets from the internal modulesor the BGW 138 are transferred 312 toward their destination via the AGW134 or the BGW 138 based on their destination address and process 300returns to block 304 for handling the next packet in the queue.

Packets from the AGW 134 are further processed and a decision is made310 whether the packet carries payload or not. If 310 the packet doesnot have a payload the process proceed to block 312 and the obtainedpacket can be transferred 312 toward its destination via the BGW 138 andprocess 300 returns to block 304 for handling the next packet in thequeue.

If 310 the packet carries a payload, then process 300 proceed to block314. Based on the IP source and destination addresses and ports the SST215 (FIG. 2) is checked 320 looking for an entry that is associated withthose addresses and ports, which means that the packet belong to anexisting session. If 320 the packet does not belong to an existingsession, then the packet is transferred 322 toward an input queue of theMM 230 (FIG. 2), allowing the MM 230 to determine how to handle the newsession. Next, process 300 returns to block 304 for handling the nextpacket in the queue of the TCP proxy 210.

If 320 the packet belongs to an existing session, then the relevantentry at the SST 215 (FIG. 2) is further processed in order to determine330 whether there is a gap in the stream of bytes between previouslyobtained packets and the current one.

If 330 a there is a gap, which means that one or more packets or bytesare missed or obtained out of order, then process 300 can respond 332 byreporting on the gap by a Selective ACK (SACK). Process 300 can proceedto block 338 and transfers the obtained packet to the relevant user'srate controller 220 a-c (FIG. 2), to be handled in block 510 (FIG. 5),which is disclosed below. In some embodiments, the relevant entry in theSST 215 can be updated indicating the gap in the stream of obtainedbytes. Next, process 300 can return to block 304 for obtaining the nextpacket in the queue.

Returning now to block 330, if a gap does not exist then at block 331 adecision is made whether the received packet fit a previous gap (missingor out-of-order packet). If it does, then a DSACK can be sent 335 andthe process proceeds to block 338. If it does not fit a previous gap,then send an ACK can be sent and process 300 proceeds to block 338. Insome embodiments, the relevant entry in the SST can be updatedaccordingly.

Using a DSACK in response to missing one or more bytes is tricky andtargeted to avoid reducing the congestion window and transmitting rateby the user's device. The DSACK spoofs the MD 110 (FIG. 1) to concludethat the originally sent packet was not lost but was receivedout-of-order, later-on. Such a conclusion at the MD 110, in an uploadsession, prevents reducing the transmitting bitrate and maintains thecurrent upload bitrate. Thus, neutralizes the rate control mechanism atthe user's device during an upload session.

Then the relevant entry in the SST 215 can be updated with informationregarding the relevant obtained bytes and the packet can be transferred338 toward the relevant user's rate controller. Next, process 300 canreturn to block 304 for obtaining the next packet in the queue.

Referring now to FIG. 4, which illustrates a flowchart with relevantactions of an example managing process 400 that can be implemented by anexample of a manager module (MM) 230 (FIG. 2). Upon initiation 402,connections with associated servers in the ANOP 130 can be set 404.Servers such as but not limited to AGW 134; BGW 138 (FIG. 1); Firewall(not shown in the figures); etc. In addition, computing and storageresources can be allocated 404 to the different modules of URCS 200.Modules such as but not limited to SST 215, UMDRC 220 a-c, (FIG. 2) etc.Preliminary data can be collected and be loaded to the appropriatemodule. Data such as the propagation delay (PD) along the differentconnections between the mobile devices 110 and the URCS 136 (FIG. 1),the time threshold (TT) used by the different intermediate nodes 132,etc.

At block 410 the queue at the ingress of MM 230 can be checked 410 fordetermining whether any upload packets are queued up. If 410 no packetsare in the queue, then the process 400 can wait until a packet is placedinto the queue. If 410 a packet exists in the upload queue, the headerof the packet can be parsed 412 and based on the source and destinationIP addresses and port values the SST 215 (FIG. 2) can be checked fordetermining whether the SST 215 (FIG. 2) is associated with those fourvalues, indicating that the packet belongs to an existing session. Thefour values of the source and destination IP addresses and ports definea session. Those values can be used as a session ID (identification)number. Next, based on searching the SST 215 a decision can be madewhether the relevant upload packet belongs to an existing session 420.

If 420 the packet belongs to an existing session, it means that therelevant packet indicating the end of the existing session. Because, twotype of packets are transferred toward the MM 230. The packets can bethe beginning of session sent (block 322 FIG. 3) transferred via the TCPproxy 210 (FIG. 2); or the end of session sent from the appropriateUMDRC 220 (as it is disclosed below in conjunction with block 514 FIG.5). Therefore, if the packet belongs to an existing session 420, itmeans that the packet indicates end-of-session (EOS). Consequently, atblock 422 resources which were allocated to that session can bereleased. Resources such as but not limited to UMDRC 220 or the relevantentry in SST 215 (FIG. 2), for example. Then process 400 can return toblock 410 for handling the next packet in the queue.

If 420 an entry does not exist in the SST 215, indicating that thepacket belongs to a new session. In some embodiments, if it's a newsession, then the header of the packet is parsed 424 in order todetermine the type of the session, is it a real time session, uploadingof large media file such as video file, etc. Based on the type of theupload session a decision can be made 430 whether a UMDRC 220 (FIG. 2)is needed. Other embodiments may handle all flows regardless of content.

If 430 there is no need for an UMDRC 220, then at block 434 an entry inSST 215 is allocated for this session. The four values of the IPaddresses and ports are written in the allocated entry and indicationthat there is no need for an UMDRC 220 is written in that entry. Thenthe packet is transferred toward its destination via the TCP proxy 210.

If 430 there is a need for an UMDRC 220, then at block 432 a UMDRC 220is allocated for the new upload session, an entry in SST 215 isallocated for that session. The four values of the IP addresses andports are written 432 and indication about the allocated UMDRC 220 iswritten in that entry. Then the packet is transferred toward the queueof the allocated UMDRC 220 and process 400 can return to block 410 forhandling the next packet in the MM queue.

Referring now to FIG. 5, which illustrates a flowchart with relevantactions of an example UMDRC task 500 that can be implemented by anexample a UMDRC 220 (FIG. 2). After initiation 502 process 500 canobtain 504 the value of the time threshold (TT) and the value of thecurrent receive window. Based on those values a value for the measuringperiod (MP) can be calculated as TT divided by ‘n’ (MP=TT:n), wherein‘n’ can be an integer number between 2-8, (4, or 5, for example). Otherembodiments may use other values for ‘n’. In addition a counter N and atimer T can be allocated 504. The counter N can count the number ofobtained bytes (NoBY). While the timer T can be used for defining theMP. The clock of the timer T can be in the range between tens tohundreds of milliseconds, for example.

The time threshold (TT) used by the intermediate nodes 132 along theconnection between the MD 110 and the URCS 136 can be found in theliterature of the cellular operator, or of the technical equipment usedin the intermediate nodes. In addition a safety factor can be used.

At block 506, counter N and the timer T can be reset and process 500 canwait 510 for obtaining an upload packet that belongs to the relevantupload session. The obtained upload packet can be parsed and if 512 itis an EOS packet, then the EOS packet indication can be transferredtoward the MM 230 (FIG. 2). At block 515 the EOS packet is transferredtoward its destination via the BGW 138 (FIG. 1) the SST 215 can beupdated and process 500 can be terminated 516. If 512 the packet is notEOS, then at block 518 the counter N can be incremented by the amount ofbytes (packet size—Ps) that are carried by the current upload packet(N=N+Ps) and the timer T can be checked 520 in order to verify that T isbigger or equal to the value of MP (T≥MP).

If 520 the value of T is smaller than MP, then at block 526 the packetis transferred toward its destination via the BGW 138 (FIG. 1). Then,process 500 can return to block 510 for handling the next packet in thequeue. If 520 the value of the timer T is equal or larger than MP, thenat block 522 a new value is calculated for the next-receive window(NRW). An example of the new value of the NRW can be calculated as thevalue of N multiplied by the value of ‘n’ and k, NRW=N*(n*k), wherein kis a tuning factor. An example value of k can be in the range between0.5 and 2. Next, the value of the NRW can be stored 524 in the relevantfield of SST 215 (FIG. 2) and the TCP proxy 210 can be updated 528 withthe new value. Then, process 500 can return to block 506 and reset thecounter N and the timer T, then at block 510 the process can wait forhandling the next uploaded packet in the queue.

Some embodiments of method 500 can repeat the actions 520 to 524 severaltimes in order to get few consecutive values for NRW, one per each cycleof action 522. Then the maximum value of the calculated NRW can beselected as the value of the NRW, which will be used for updating theTCP proxy at block 528.

The present disclosure describes few methods that can be used by a URCS136 in order to improve and accelerate the rendering of an uploadsession from a mobile device 120 toward a web server 150 (FIG. 1). Inanother example embodiment a SACK and DSACK can be used for requesting amissing packet without reducing the congestion window to half of thecurrent used congestion window. An example of such technique isdisclosed above in conjunction with FIG. 3.

In the description and claims of the present application, each of theverbs, “comprise”, “include” and “have”, and conjugates thereof, areused to indicate that the object or objects of the verb are notnecessarily a complete listing of members, components, elements, orparts of the subject or subjects of the verb.

The present invention has been described using detailed descriptions ofembodiments thereof that are provided by way of example and are notintended to limit the scope of the invention. The described embodimentscomprise different features, not all of which are required in allembodiments of the invention. Some embodiments of the present inventionutilize only some of the features or possible combinations of thefeatures. Many other ramification and variations are possible within theteaching of the embodiments comprising different combinations offeatures noted in the described embodiments.

It will be appreciated by persons skilled in the art that the presentinvention is not limited by what has been particularly shown anddescribed herein above. Rather the scope of the invention is defined bythe claims that follow.

The invention claimed is:
 1. A method comprising: (a) employing anupload-rate-controlling server (URCS) that is communicatively coupledbetween a plurality of mobile devices (MD) through an access gateway(AGW) and a plurality of Internet Protocol (IP) servers; (b) the AGWbeing configured to perform the actions of: (i) intercepting at leastone stream of packets from a plurality of the streams of packets thatare transferred between one of the MDs from the plurality of MDs and oneof the IP server from the plurality of IP servers; (ii) determining thatthe intercepted stream of packets belong to an upload session; and (iii)transferring the intercepted stream of packets to the URCS (c) the URCSbeing configured to perform the action of manipulating the one MD fromthe plurality of MDs to maintain a transmitting rate of the interceptedstream of packets of the upload session.
 2. The method of claim 1,wherein the URCS is configured to perform the actions of manipulatingthe one MD from the plurality of MDs to maintain the transmitting rateof the intercepted stream of packets of the upload session by: (1)determining that one or more packets are missed in the interceptedstream of packets; (2) sending, toward the one MD, a selectiveacknowledge (SACK) packet indicating the one or more packets that aremissed; (3) obtaining the one or more missed packets; and (4) sending aduplicating-selective ACK (DSACK) indicating that the obtained one ormore packets were not missed but were obtained out of order.
 3. Themethod of claim 1, wherein the intercepted stream of packets that belongto the upload session carry media content.
 4. The method of claim 1,wherein the action of manipulating the one MD to maintain thetransmitting rate of the intercepted stream of packets of the uploadsession, further comprising adapting a value of a receive window senttoward the MD to be based on a number of bytes obtained from the one MDwithin a measure period (MP).
 5. The method of claim 4, wherein the MPis based on a time threshold (TT) used by intermediate nodes, locatedover connection between the one MD and the URCS, for dropping storedpackets of the intercepted stream of packets that belong to the uploadsession.
 6. The method of claim 5, wherein the URCS is furtherconfigured to perform the action of calculating a value of a nextreceiving window (NRW) proportional to an amount of bytes that areobtained (NoBY) during an MP and a number of MP that are included in theTT.
 7. The method of claim 1, wherein the URCS is further configured tocontrol the transmitting rate of the one MD by: (a) estimating a delayof the intercepted stream of packets of the upload session; (b) adaptingthe value of a next receive window (NRW) such that the delay of theintercepted stream of packets of the upload session is smaller than avalue of a time threshold (TT) used by intermediate nodes along theupload connection for dropping packets.
 8. The method of claim 7,wherein the NRW is proportional to the value of TT andinversely-proportional to the transmitting rate of the interceptedstream of packets of the upload session.
 9. The method of claim 1,wherein the URCS is further configured to perform the action ofcalculating a delay of the intercepted stream of packets by: (a)obtaining a value for a propagation delay along one or more intermediatenodes; (b) measuring a value of a round trip time (RTT) of theintercepted stream; and (c) reducing the value of the propagation delayfrom the value of the RTT.
 10. The method of claim 9, wherein in orderto measure the RTT during an ongoing upload session the URCS is furtherconfigured to perform the actions of using a unique receiving window,which is substantially greater than a receiving window that is mostlyused in the upload session.